我们采用多组件数学模型，使用单等中心照射治疗脑转移瘤的立体定向放疗（SRT）考虑六个自由度（6DoF）患者位移误差，评估了肿瘤残留容积。使用模拟的球形毛发状肿瘤体积（GTVs）进行评估，分别为1.0（GTV 1）、2.0（GTV 2）和3.0（GTV 3）厘米的直径。把GTV中心与等中心之间的距离设置为0-10厘米。使用仿射变换，在三个轴向内同时进行0-1.0毫米（T）平移和0°-1.0°（R）旋转GTV。我们使用非小细胞肺癌细胞株（A549和NCI-H460）生长的测量结果来优化肿瘤生长模型参数。在GTV大小、d和6DoF设置误差变化时，使用GTB物理剂量计算辐照结束时GTV剩余容积。根据术前GTV体积，确定满足容忍度值（10％、35％和50％）的d值。对于两种细胞系，容忍度值设置越大，满足容忍度值的距离就越远。在基于多组件数学模型的SRT单等中心照射下进行的GTV剩余容积评估中，GTV大小越小，距离越大，6DoF设置误差越大，满足容忍度值的距离就可能越短。 © 2023澳大拉西亚物理科学和工程医学学院。

We evaluated the tumor residual volumes considering six degrees-of-freedom (6DoF) patient setup errors in stereotactic radiotherapy (SRT) with multicomponent mathematical model using single-isocenter irradiation for brain metastases. Simulated spherical gross tumor volumes (GTVs) with 1.0 (GTV 1), 2.0 (GTV 2), and 3.0 (GTV 3)-cm diameters were used. The distance between the GTV center and isocenter (d) was set at 0-10 cm. The GTV was simultaneously translated within 0-1.0 mm (T) and rotated within 0°-1.0° (R) in the three axis directions using affine transformation. We optimized the tumor growth model parameters using measurements of non-small cell lung cancer cell lines' (A549 and NCI-H460) growth. We calculated the GTV residual volume at the irradiation's end using the physical dose to the GTV when the GTV size, d, and 6DoF setup error varied. The d-values that satisfy tolerance values (10%, 35%, and 50%) of the GTV residual volume rate based on the pre-irradiation GTV volume were determined. The larger the tolerance value set for both cell lines, the longer the distance to satisfy the tolerance value. In GTV residual volume evaluations based on the multicomponent mathematical model on SRT with single-isocenter irradiation, the smaller the GTV size and the larger the distance and 6DoF setup error, the shorter the distance that satisfies the tolerance value might need to be.© 2023. Australasian College of Physical Scientists and Engineers in Medicine.